|
|
||||||||
Papers In Press, published online ahead of print March 19, 2007
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vascular Research, Johnson & Johnson, PRD, Spring House, PA 19477-0776
Corresponding Author: mconnell{at}prdus.jnj.com
Scavenger receptor BI, SR-BI, facilitates the uptake of high density lipoprotein (HDL) cholesteryl esters (CE) in a two step process involving binding of HDL to its extracellular domain and transfer of HDL core CE to a metabolically active membrane pool where they are subsequently hydrolyzed by a neutral CE hydrolase. Recently we characterized a mutant, G420H, which replaced glycine 420 in the extracellular domain of SR-BI with a histidine residue and had a profound effect on SR-BI function. The G420H mutant receptor exhibited a reduced ability to mediate selective HDL CE uptake and was unable to deliver HDL CE for hydrolysis, despite the fact that it retained the ability to bind HDL. This did not hold true if glycine 420 was replaced with an alanine residue; G420A maintained wild type HDL binding and cholesterol transport activity. In order to further understand the role that glycine 420 plays in SR-BI function and why there was a disparity between replacing glycine 420 with a histidine versus an alanine, we generated a battery of point mutants by substituting glycine 420 with amino acids possessing side chains that were either charged, hydrophobic, polar or bulky and tested the resulting mutants for their ability to support HDL binding, HDL cholesterol transport and delivery for hydrolysis. The results indicated that it is most likely the positive charge on the histidine side chain that disrupts the ability of SR-BI to deliver HDL CE to a metabolic pathway within the cell.
Accepted on March 19, 2007
Effects of amino acid substitutions at glycine 420 on SR-BI cholesterol transport function
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
B. Elbaz, A. Alperovitch, M. M. Gottesman, C. Kimchi-Sarfaty, and H. Rahamimoff Modulation of Na+-Ca2+ Exchanger Expression by Immunosuppressive Drugs Is Isoform-Specific Mol. Pharmacol., April 1, 2008; 73(4): 1254 - 1263. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |